Hprt1^tm1Detl

A construct was created that introduced a long CAG repeat (n=146 units) into an Xho1 site in exon 3 of a genomic fragment of the locus. An additional 4.9kb genomic fragment, which included exon 4 of the gene, was added to this repeat-containing construct. Appropriately targeted clones had sequences containing the 146-unit CAG repeat, encoding a stretch of 146 glutamines, in place of wild-type exon 3. (J:44728)